AutoCodes – Generic – B0126

B0126 Code - Left Front Seat Belt Buckle Switch Malfunction

Quick Answer

The left front seat belt buckle switch circuit consists of the air bag center sensor and left front seat belt buckle assembly. Common causes include Faulty Left Front Seat Belt Buckle Switch, Left Front Seat Belt Buckle Switch harness is open or shorted, Left Front Seat Belt Buckle Switch circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B0126 indicates Left Front Seat Belt Buckle Switch Malfunction.
Common causes: Common causes include Faulty Left Front Seat Belt Buckle Switch, Left Front Seat Belt Buckle Switch harness is open or shorted, Left Front Seat Belt Buckle Switch circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,345

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code B0126 Description

The left front seat belt buckle switch circuit consists of the air bag center sensor and left front seat belt buckle assembly. The Air Bag Control Module monitors the Left Front Seat Belt Buckle Switch. The Air Bag Control Module sets the OBDII code when the Left Front Seat Belt Buckle Switch is not to factory specifications.

OBDII Code B0126 - Left Front Seat Belt Buckle Switch Malfunction - AutoCodes.com — B0126 Code - Left Front Seat Belt Buckle Switch Malfunction

What does this mean?

What are the Possible Causes of the DTC B0126?

Faulty Left Front Seat Belt Buckle Switch
Left Front Seat Belt Buckle Switch harness is open or shorted
Left Front Seat Belt Buckle Switch circuit poor electrical connection
Faulty Air Bag Control Module

How to Fix the DTC B0126?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B0126 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B0126 code?

Need more information on how to fix the B0126 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0126 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B0126 Lexus — Left Front Seat Belt Buckle Switch Malfunction
B0126 Scion — Left Front Seat Belt Buckle Switch Malfunction
B0126 Toyota — Left Front Seat Belt Buckle Switch Malfunction

Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.

Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.